Abstract

The deactivation of Pt/WO_x/Al₂O₃ and Pt-Ru/WO_x/Al₂O₃ catalysts in the glycerol hydrogenolysis to 1,3-propanediol (1,3-PDO) was investigated in autoclave. The selectivity of both catalysts toward 1,3-PDO was within 50–56% after the first five usages at 170 °C for 12 h with a H₂ pressure of 9 MPa. With Pt/WO_x/Al₂O₃, the conversion of glycerol decreased from 44.3% (1st reaction) to 27.2% (5th reaction), whereas a conversion of 52.4%, 48.0%, and 48.4% was obtained in the 1st, 5th, and 20th reactions, respectively, when Pt-Ru/WO_x/Al₂O₃ was used. The characterizations of the catalysts showed that the pore structure of the catalyst changed because of the crystal structure of the catalyst support changing from γ-Al₂O₃ to pseudo-boehmite. However, the changes of the catalyst morphology were not responsible for the catalyst deactivation. Simultaneously, the acidity of catalysts was not shown to be a factor in their deactivation. On the other side, catalysts were not deactivated as a result of the loss of active components. Catalyst deactivation during glycerol hydrogenolysis was finally caused by the aggregation of active metal particles (Pt or Pt-Ru).

摘要

_{研究了Pt/WO x} /Al ₂ O ₃和Pt-Ru/WO _x /Al ₂ O ₃催化剂在高压釜中甘油氢解制1,3-丙二醇(1,3-PDO)过程中的失活情况。_{在前五次在 170 °C 下使用 12 小时且 H 2}压力为 9 MPa后，两种催化剂对 1,3-PDO 的选择性在 50-56% 以内。使用 Pt/WO _x /Al ₂ O ₃时，甘油的转化率从 44.3%（第 1 个反应）下降到 27.2%（第 5 个反应），而第 1 个反应的转化率为 52.4%、48.0% 和 48.4%，当 Pt-Ru/WO _x /Al ₂ O时，分别是第 5 个和第 20 个反应使用了_{3 个。}催化剂的表征表明，由于催化剂载体的晶体结构由γ-Al ₂ O ₃转变为假勃姆石，催化剂的孔结构发生了变化。然而，催化剂形态的变化并不是催化剂失活的原因。同时，催化剂的酸度并未显示是其失活的一个因素。另一方面，催化剂并没有因为活性成分的损失而失活。甘油氢解过程中的催化剂失活最终是由活性金属颗粒（Pt 或 Pt-Ru）的聚集引起的。